In: Statistics and Probability
The business problem facing the director of broadcasting operations for a television station was the issue of standby hours (i.e hours in which employees at the station are paid but are not actually involved in any activity) and what factors were related to standby hours. The study included the following variables:
Standby Hours (Y)- Total number of standby hours in a week.
Weekly staff count (X1)- Weekly total of people-days
Remote engineering hours (X2)- Total number of engineering hours worked by employees at locations away from the central plant.
Data was collected for 26 weeks:
Standby | Total Staff | Remote |
245 | 338 | 414 |
177 | 333 | 598 |
271 | 358 | 656 |
211 | 372 | 631 |
196 | 339 | 528 |
135 | 289 | 409 |
195 | 334 | 382 |
118 | 293 | 399 |
116 | 325 | 343 |
147 | 311 | 338 |
154 | 304 | 353 |
146 | 312 | 289 |
115 | 283 | 388 |
161 | 307 | 402 |
274 | 322 | 151 |
245 | 335 | 228 |
201 | 350 | 271 |
183 | 339 | 440 |
237 | 327 | 475 |
175 | 328 | 347 |
152 | 319 | 449 |
188 | 325 | 336 |
188 | 322 | 267 |
197 | 317 | 235 |
261 | 315 | 164 |
232 | 331 | 270 |
a.) state the multiple regression equation (show work)
b.) interpret the meaning of the slopes, b1 and b2, in this problem. (show work)
c.)Explain why the regression coefficient, b0, has no practical meaning in the context of this problem.
d.) Predict the mean standby hours for a week in which the weekly staff recount was 310 people-days and the remote engineering hours total was 400 (SHOW WORK)
e.) what is the p-value and interpret its result? (SHow work)
***Please use In depth Excel or PHStat to verify the answers. showing the steps to doing the problem is very helpful to me so I can better understand how to do the whole process.
Using Excel, go to Data, select Data Analysis, choose Regression. Put Standby in Y input range and Total Staff and Remote in X input range.
SUMMARY OUTPUT | |||||
Regression Statistics | |||||
Multiple R | 0.700 | ||||
R Square | 0.490 | ||||
Adjusted R Square | 0.446 | ||||
Standard Error | 35.387 | ||||
Observations | 26 | ||||
ANOVA | |||||
df | SS | MS | F | Significance F | |
Regression | 2 | 27662.543 | 13831.271 | 11.045 | 0.000 |
Residual | 23 | 28802.073 | 1252.264 | ||
Total | 25 | 56464.615 | |||
Coefficients | Standard Error | t Stat | P-value | ||
Intercept | -330.675 | 116.480 | -2.839 | 0.009 | |
Total Staff | 1.765 | 0.379 | 4.656 | 0.000 | |
Remote | -0.139 | 0.059 | -2.363 | 0.027 |
a) Standby = -330.675 + 1.765*Total Staff - 0.139*Remote
b) b1: With one unit increase in total staff, standby hours increase by 1.765
b1: With one unit increase in remote engineering hours, standby hours decrease by 0.139 hours
c) b0 signifies that if both weekly staff count and remote hours are zero, standy hours will be -330.675. This is not possible as hours cannot be less than zero.
d) Remote = 400, Total staff = 310
Standby = -330.675 + 1.765*Total Staff - 0.139*Remote\
Standby = -330.675 + 1.765*310 -0.139*400
= 160.875 hours
e) H0: The model is not a good fit
H1: The model is a good fit
p-value (Significance F) = 0.000
Since p-value is less than 0.05, we reject the null hypothesis and conclude that the model is a good fit.